In the United States the two main pricing guides are: the Kelley Blue Book and the N.A.D.A. guides.

Personally I like very much the N.A.D.A. guides. They give faithful information about almost every motor vehicle produced since 1933, and several configuration options to help you get an accurate value of your motorcycle or the one you want to buy.

The National Automobile Dealers Association (N.A.D.A.) is nowadays the largest publisher of Appraisal Guides in the world. Their guides provide information for most of the motor vehicles ever made: cars, motorcycles, boats, recreation vehicles and more. Since 1933, N.A.D.A. has been helping buyers to make informative, responsible and safe decisions when buying motor vehicles.

The N.A.D.A. guide for motorcycles are better know as: the "Motorcycle Blue book".

THE MARKET

Another way to check for prices is to look into your local market. You can do it online and/or offline. Search in the newspaper, bulletin boards, classified adds, E-Bay, shops, friends. Compare prices take a look at the physical condition of different used motorcycles.

RECOMMENDATION

Prices may vary (sometimes a lot) depending where in the world you are located in. So, always check in the books AND in your local market to get accurate values.